1. Field of the Invention
The present invention relates to an endoscope system with a rotating treatment adapter at the end. More particularly, this invention is concerned with an endoscope system having a mounting mechanism for preventing the falling of a rotating treatment member to be mounted at the end of a torque coupling member.
2. Description of the Prior Art
In recent years, an industrial endoscope allowing a worker to check the inside of a pipe or an engine at a chemical plant without disassembling it has been adopted widely.
For example, an endoscope is used to check a jet engine. Then, a defect or other damage may be detected on the edge of a turbine blade which is driven to rotate. In this case, even a minor damage causes concentration of stress, supposing it is left intact. As a result, the damage grows to necessitate replacement of the blade unit.
Therefore, in the past, even when replacement is not needed, if a damage is detected, the engine has been disassembled to grind the cracked part and its surrounding area. This procedure is, however, time-consuming.
In an endoscope of prior art disclosed, for example, in Japanese Patent Laid-Open No.58-162924, a grindstone or other rotating treatment member is mounted to the distal end of the endoscope. Then, the rotating treatment member is inserted into a jet engine to grind a damaged part.
This kind of rotating treatment member is often mounted to the end of an insertion tube of an endoscope to be detachable from a torque transmission member for transmitting torque via a tightening means including a screw, a three-claw chuck, and a collet chuck. Thus, the rotating treatment member can be changed depending on the purpose of treatment or use.
For example, when the blade of a jet engine is treated using an endoscope having a rotating treatment member, a grindstone must be assuredly prevented from falling into the engine.
In general, when a metal plate is ground, the ground portion of the metal plate is misshaped depending on the rotating direction of a grindstone. Therefore, the rotating direction of a grindstone must be changed selectively. Assuming that a grindstone is attached or detached using a screw, when the grindstone is pressed to a blade for treatment, if it is rotated in the direction of loosening the engagement with a torque transmission member, it will fall off. Therefore, the rotating direction is confined to one direction and cannot be changed selectively.
A three-claw chuck or a collet chuck uses frictional force alone to fix a grindstone to a torque transmission member. Therefore, if the chuck is loosened even slightly, it may cause the grindstone to fall off. The use of an endoscope having a rotating treatment member fixed with a three-claw or collet chuck must be allowed only under the conditions that the relationship between tightening force and transmission torque is well-understood and it is confirmed that the grindstone will not fall off. Thus, when an endoscope having a rotating treatment member fixed with a three-claw or collet chuck is employed, it must be checked whether the use of the endoscope is limited or not. This deteriorates workability.